Automatic stop for elevators.



P. L. MANLET.

AUTOMATIC STOP FOR ELEVATORS.

APPLICATION IILED MAYQ, 1911.

1,032,363. Patented July 9, 1912.

PETER I1. MANLET, OF ST. PAUL, MINNESOTA, ASSIGNOR OF ONE-FOURTH TO WILLIAM J. KOUT, OF ST. PAUL, MINNESOTA.

AUTOMATIC STOP FOR ELEVATORS.

oeaecs.

Specification of Letters -Patent.

Patented Julyt), 1912.

Application filed May 9, 1911. Serial No. 625,948.

To all whom it may concern:

Be it known that I, PETER L. MANLET, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Automatic Stops for Elevators, of which the following is a specification.

My invention relates to improvements in automatic stops for elevators and its principal object is to provide a positive means for throwing off the power operating the elevator when the elevator car or the counterweights connected with it are carried beyond a predetermined point in their respective guide tracks.

It frequently happens that an elevator operator is unable to shut off his power in time to prevent the car from rising too high in the elevator shaft, damaging the car and shaft and tending to break the elevator cable through the momentum of the counterweights. Numerous devices are in use intended to apply brakes to the elevator car when it passes beyond its upper or lower limits, but which are frequently slow to operate or entirely ineffective.

The device which I have invented operates positively and instantly to cut off the power operating the elevator and stop the elevator, thus preventing accidents through carelessness on the part of the operator or defective controlling devices.

In the drawing with which I have illus trated my invention and which forms part of my specification, Figure l is a perspective view showing diagrammatically the operation of my device in connection with an elevator; Fig. 2 shows the method of attaching my device in an elevator shaft, and Fig. 3 illustrates the operation of my device to control a mechanical brake.

In Fig. 1 I have illustrated a main circuit switch A supplying power to the motor of the elevator which is not shown, an ordinary motor supplied with an electric brake being understood as operating an elevator car which moves in the car track B illustrated.

A counter-weight guide C is shown in which slide the counter-weights 2 connected to the elevator car in the ordinary manner by cables 3. The guides C are formed with grooves t carrying the ends of the counterweights 2. The track 13 also has a groove 5 or equivalent trackway to receive a guide part on the elevator car.

My device consists of a frangible peg or stop pin 6 fixed in the guide groove 5 of the track B in the path of the elevator car and carrying a flexible cord or chain 9 connected with an operating weight D. The weight D is connected by a similar flexible cord 8 with the movable handle part 9 on the switch A in such manner as to throw the switch and break the power circuit through the dropping of the weight D when the elevator car passes over the frangible peg (3. The peg 6 may be placed in the groove 5 near the top of the elevator shaft as shown in Figs. 1 and 2 thus breaking the circuit and stopping the car when it rises too high in the elevator shaft, or it may be placed in the groove 4 near the upper end of one of the guides C where the counter-weights 2 will operate the circuit breaker A when the car has descended too low, bringing the counterweights dangerously near the top of the guideway.

In Fig. 1 I have illustrated a flexible cord 7 passing over suitable pulleys 10 and 11 and connected to pegs 6 in the tracks B and C. The weight D is shown supported by a cord 12 passing over a suitable pulley 13 and fastened to an eye 14: attached to a sheave 15 through which passes the cord 7. The breaking of either of the pins 6, freeing the cord 7 allows the sheave 15 to move along the cord 7 dropping the weight D. The cord 8 connected to the weight D passes over suitable pulleys l6 and 17 in such manner that the falling weight D pulls upon the handle 9 of the switch A and opens it.

The switch A is shown connected with the electric terminals 19 and 20 which are connected with the elevator motor and any suitable source of power. The switch may be mounted at the top of the elevator shaft as indicated or in any convenient location, the proportion of the operating parts being accommodated to the position of the switch A and stops 6 so that they may operate in the manner described. If desired a guide may be provided for the weight D, which may be of any convenient form.

The stops 6 may be placed at the top or bottom of the grooves in which they are shown or otherwise placed in the path of the counterweight or of the car in whichever manner is most convenient to place the desired limits of movement of the car in its shaft, such for instance as by plaemg one stop at the bottom of one counterweight groove of a pair and the other stop at the top of the companion groove.

In Fig. 3 a single stop 6 is shown in the elevator track B with a cord 2l-connecting over suitable pulleys 22 with a weight arm 24L of a mechanical brake E which may be applied to a friction wheel 25 either upon the motor of the elevator or upon any of the rotating parts of the elevating mechanism. The brake E shown has a support-ing frame 26 with friction arms 27 pivoted on the frame 26 and lying in contact with the friction wheel 25 and adapted to be operated by the brake arm 2a which is also pivoted on the frame.

A circuit breaker A is shown in connection with the brake E, being fitted with an operating cord 28 passing over suitable pulleys 29 and connecting with the cord 21 to be operated by the weight F of the weight arm 24 when the stop 6 is broken. It is evident that the weight F on the arm 24 of the brake E performs the same function as the weight D illustrated in Fig. 1 and the brake E may be used alone or in connection with the circuit breaker A. Then used in connection with the circuit breakerthe brake E serves to supplement the electric brake usually found upon the motors of electric elevators. The brake E used alone adapts my device to elevators operated by other than electric power.

In accordance with the patent statutes I have described the principles of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof but I desire to have it understood that the construction shown is only illustrative and that the invention can be carried out by other means and applied to uses other than those above set forth within the scope of the following claims.

Having described my invention, what I claim as new and .desire to protect by Letfers Patent is 1. A stop for an elevator, comprising, in combination, an elevator car, a power supply connection, an operating weight, a frangible peg to support said weight and interposed in the path of said car, means connecting said weight with said power supply connection and adapted to break said connection and stop said car when the car has broken said frangible pe z 2. An'elevator having a car, power operating means for said car, and means for throwing off the power when said elevator car moves beyond a fixed limit of travel, consisting of a frangible peg associated with said power means and interposed in the path of an operating part of said elevator adapted to be broken by the operation of said elevator beyond said fixed limit to discontinue the actuation of said elevator.

3. An elevator having electric means including an operating circuit for controlling its movement and adapted to travel within a fixed limit, a circuit breaker included in said means to open its operating circuit,

'means for opening said circuit breaker, a

frangible device normally holding said opening means out of operation and adapted to be broken by the action of abnormal movement of the operating part of said elevator and permit said opening means to open said circuit breaker. ft. A device of the class set forth, comprising, in combination, an elevator car, a guideway, a counterweight for said car operating in said guideway, a power connection for actuating said car and moving said counterweight within fiXed limits in said guideway, and an actuating device including a frangible connect-ion fastened to said power connection and in the path of said counterweight to be broken by the movement of said counterweight when traveling beyond said fixed limits and thereby interrupt said power connection and stop said counterweight.

5. An elevator having electric means for raising and lowering the same and adaptedto travel within fixed limits, an electric circuit connected with said means for actuating said elevator, a circuit breaker included in said circuit and a frangible device connected to said circuit breaker and adapted normally to remain immovable and by the action of abnormal movement of an operating part of said elevator to be broken and cause said circuit breaker to open said circuit.

(3. An elevator car and a coactive part adapted to move in a limited path during the normal travel of said elevator car, electric means for operating said car having an electricv circuit included therein, a circuit breaker in said circuit to open the same and stop said elevator, and frangible means connected with said circuit breaker to operate the same interposed in the path of said m0v-' able part at the limit of its normal travel and adapted to be broken by further travel of said part toopen said circuit and stop said elevator.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

PETER L. MANLET.

' WVitnesses:

'H. L. FIsoHER, F. G. BRADBURY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

